I do agree to an extent. Instead of Dowolf doing the whole thing again, he could just go through Kosuna's translation as was planned before. That would ensure the quality of translation and it would be faster too.
I'm assuming that Kosuna has already sent the 99% translation. If he hasn't then I think he can complete whatever he has left and give it soon. 99% indicates that his translation is more or less complete, if he wants to check his work I think it would be faster and better if Dowolf checked it rather.